Targets:
1. Acquire 4 Marines, 2 Tempest, 6 Terminators; 8 Artemis Tanks (You have already 3 from the Ashrock location) and Commander Thadius to fill requirements to dominate the first 3 missions and unlock the next location.
2. Once acquired Commander Thadius at 1st mission (Assault the Arctis Mines) active him into your Force with Anastasia. By now you ought to have your Assault slots covered with Rocket Infantry (continue with Infiltrators if you cannot afford them)
3. If you get rewarded the Aegis Assault unit during the domination of 3rd mission (Divine Shield), equip it into your Force. If you didn't get Aegis, don't delay your progress and leave it. You can always return later to add it into your Force.
4. Dominate the first 3 main missions and advance to the next location: Caverns, for a faster and efficient progress.
Chance Loot: Commander: Thadius (24/16), 15% chance
If you dominated at 100% this mission but didn't got Thadius, continue doing this mission untill he drops.
NOTE: This unit is awesome. This one will start even best once you will raise your defensive stat (not in this leveling phase). It is one of the "must" units for defensive setups in High Levels.
Advice:
Due his low drop rate, I suggest you forget this unit untill you become done with ALL locations (if that didn't dropped yet while dominating this mission till 100%). Continue your progression and return later once all other primary goals were done.
MOVE FORWARD. Continue your advance in the next location, Caverns
Advice:
This structure useful in the past, don't worth the effort trying to get it. Get rid on it.